It is recommended that you replace the filter every six months or as needed to help maintain vacuum function as well as maintain optimal filtration inside of your home. Stop washing your old foam filter round blocks all the time and get new， clean ones if you crave for faster and more efficient cleaning.<br /><br />Features:<br />1. Fit for Shark models NV500， NV500CO， NV501， NV502， NV503 and NV500W<br />2. Replaces for Shark part numbers XFF500 and XHF500<br /><br /><br /><br />Specification: <br />Material: Foam <br />Color: white<br />Foam Filter Size: 9 x 10.4cm <br />Felt Filter Size: 10.7cm<br /><br />Package included:<br />1 x Foam Filter<br />1 x Felt Filter